The present invention generally relates to a golf putter. More specifically, the present invention relates to a putter having multiple fixed lie angles or an adjustable-lie position hosel, an interchangeable and weighted striking face plate for providing various lofts and weights, a sole shape facilitating loft lie and directional alignment while resting on the ground and improved "swale sight system" with set-up alignment and sighting features.
Putting performance is greatly dependent on a golfer's ability to precisely align and aim the club head relative to the ball path and hole. Therefore, a goal in putter design has been to provide sighting aids which assist a golfer in achieving correct alignment and optimum aim.
Proper club alignment is desired in lie, loft, striking direction, centering of the ball relative to the club head "sweet spot" and parallel-to-the-ground striking point on the club face. These terms, as used herein, have meanings conventional in golf: "lie" is an angle between a heel-to-toe line and an axis of the shaft; "loft" is an angle of the striking face plane from vertical; "striking direction" a vector parallel to the ground and which is 90.degree. from the striking face; "sweet spot" is the optimum striking point between the club head and ball which creates correct distance and direction.
In order to assist a golfer to visually align a putter head, club heads are known to have visual markings. In a textbook putting stance, a golfer's eyes should be generally looking vertically downward over a centerline of the putter head. Thus, visual markings are generally designed to help a golfer align the club from this perspective. Much study has been directed toward attempts to improve a putter's ease of visual alignment. For example, U.S. Pat. No. 4,136,877 relates to a putter having markings on two vertical levels, the alignment of the markings indicating whether the club head is level.
Currently-available putters include sight lines that extend along the top of the putter head. While these sight lines extend along the target direction, they do not take into account the loft of the putter. That is, sight lines are not perpendicular to the face of the putter but only perpendicular to a vertical plane. Accordingly, because most putters have a loft ranging from 2.degree. to 5.degree., the sight lines are not truly perpendicular to the face of the putter. It has been found that this lack of a perpendicular relationship between the face of the putter and the sight line is a disadvantage and can lead to less accurate putting. This problem is compounded when putters are equipped with a rearwardly extending flange. The top surface of the flange is typically lower than the top surface of the portion of the putter head adjacent to the striking face. As a result, if sight lines are provided on the rearwardly extending flange, they are not connected to the sight lines disposed on top of the putter head but are generally parallel to and disposed below the sight lines provided on top of the putter head. Because these sight lines too are generally not perpendicular to the striking face, the golfer has two parallel sets of sight lines to look at, neither of which are perpendicular to the striking face. Again, this combination has been found to be a great disadvantage that leads to putting inaccuracy.
Because golfers vary in body size and proportion, optimum club fit varies from person to person. The angle of the club head relative to the shaft, or "lie," is one such design aspect which must be determined for each golfer. Therefore, for a custom fit, it is desirable to provide a hosel which provides multiple fixed lie angles or adjustability of the lie.
Adjustable-lie putters, although rare, have previously been attempted. One known type has a ball-and-socket structure integral to a heel of the putter head to which the shaft is attached. By rotating the shaft, a screw mechanism loosens and tightens the ball in the socket at a selected orientation. The "Sprague Patent Putter," circa 1903, and a "Zebra" putter, circa 1970, each incorporate such a feature. Another known adjustable-lie putter known as a "Select-A-Putt," U.S. Des. Pat. No. 205,672 has an expandable friction lock between the shaft and putter head at an apex of the center and face of the putter head. A putter known as the "Barnes Patent Putter", made around the early or mid-1920's, has a locking tooth mechanism between the shaft and putter head, located at an apex of the heel and face of the putter head. That system permits lie adjustment in only a few finite increments.
Unfortunately, the USGA rules forbid readily adjustable putters. Specifically, " . . . forms of adjustability are permitted in the design of a putter, provided that: (i) the adjustment cannot be readily made; (ii) all adjustable parts are firmly fixed and there is no reasonable likelihood of them working loose during a round . . . " USGA Rules of Golf, Rule 4-1a (1995) (in pertinent part). The USGA interpreted this rule as prohibitive of an arrangement which was merely utilized friction tightened by a set screw. It is desirable to provide a putter with an adjustable-lie hosel which is permissible for play within the USGA rules of golf.
Putters are conventionally designed so that the striking face has a slight loft. A putter's loft generally ranges from 2-5.degree., but loft may be greater or smaller, if desired. Such loft slightly lifts the ball from the green during initial contact with the putter. Such a lifting effect is, in general, usually desirable so that the ball achieves momentum in the desired direction while overcoming resistance from the turf. Without any loft, or with a negative loft, the ball may push into the turf, slowing the putt, possibly causing it to react off of the turf in an undesired direction.
Putting greens have varying characteristics. Greens may vary in softness, dampness, length and texture of grass, all factors which may effect a putt. Any one particular green may experience changed characteristics even during a day. For a particular golfer, geographic region, or differing putting green characteristics, a particular putting face may result in better control and accuracy. Therefore, it is desirable to provide a putter having a selectable putting face material, loft, profile, color, sound, reflex, vibrational feedback and/or feel.
Also, weight distribution is another important aspect of putter design. Much study has been directed to placement of concentrated weights in putters. It is desirable to provide a putter head which is weighted for optimal putter feel and swing balance, as well as putting distance, control and accuracy. Also, as with other putter features, it may be desirable that such weights be adjustable in amount.
Also, the bottom surface of many putters includes a simple rectangular or arcuate configuration. Thus, the putter can "rock" or "glitch" on the putting surface as the golfer lines up the putt. As a result, the putter head can be difficult to aim easily or improperly tilt toward or away from the golfer which will adversely affect alignment and accuracy.
Finally, many putters include a hosel which is connected to the putter head at an angle. This angled connection between the putter head an the shaft also contributes to the tendency of the golfer to misalign the putt.
Thus, there is a need for an improved putter which addresses at least some, if not all of the above deficiencies including an easy way to adjust the lie of the putter, the weight and weight distribution of the putter head, the loft of the putter, face and material improved ways to visually align the striking face and improve ways to properly ground the putter.